A Turkish aid group said on Monday it would send ships again to challenge the Israeli blockade of Gaza, four years after Israeli commandos stormed its flotilla bound for the Palestinian territory and killed 10 people.

The incident wrecked diplomatic ties between Turkey and Israel, once close Middle East allies but whose relationship has been tense since late 2008 over a previous Israeli military operation against Islamist militants dominating Gaza.

The Marmara being towed into port in Haifa. (Photo: Shay Vankin)

The Humanitarian Relief Foundation (IHH) said in an e-mailed statement that members of a "coalition" of pro-Palestinian activists from 12 countries had met in Istanbul at the weekend and decided to launch a convoy "in the shadow of the latest Israeli aggression on Gaza," referring to the latest, month-long war. Fighting has abated under a 72-hour ceasefire deal.

"The Freedom Flotilla Coalition affirmed that, as most governments are complicit, the responsibility falls on civil society to challenge the Israeli blockade on Gaza," it said.

An IHH spokeswoman did not elaborate. The group will hold a news conference on Tuesday, she said.

Nine Turks died in May 2010 in international waters after Israeli soldiers raided their vessel, the Mavi Marmara, leading a flotilla to break Israel's seven-year blockade of Gaza. A 10th Turkish activist died in May from wounds suffered in the attack.

Turkish Prime Minister Tayyip Erdogan, who on Sunday was elected president, has been among the most vocal critics of Israel's conflict with the Islamist Hamas movement that rules the Gaza Strip.